Problems engraving text
I used the boolean difference method as described on the boards as well, but it can do funky stuff to your geometry if, for example, you were engraving the inside of a cylinder (like a ring). Instead, I prefer to go into UV editing mode, select the faces where I want the text to be, then unwrap the UVs to a new map. From there you can export the UVMap or import the image you exported from Illustrator and apply it to the UVMap. Now, apply the image as a texture to the object, add a displacement modifier and apply the texture to the UVMap.
More on displacement modifier here there are tons of tutorials to be searched for.